<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2013 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * @category       PHPExcel
 * @package        PHPExcel_Calculation
 * @copyright      Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license        http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version        1.7.9, 2013-06-02
 */


/** PHPExcel root directory */
if (!defined('PHPEXCEL_ROOT'))
{
	/**
	 * @ignore
	 */
	define('PHPEXCEL_ROOT', dirname(__FILE__) . '/../../');

}


/** EULER */
define('EULER', 2.71828182845904523536);


/**
 * PHPExcel_Calculation_Engineering
 *
 * @category       PHPExcel
 * @package        PHPExcel_Calculation
 * @copyright      Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Calculation_Engineering {

	/**
	 * Details of the Units of measure that can be used in CONVERTUOM()
	 *
	 * @var mixed[]
	 */
	private static $_conversionUnits = array(
			'g' => array('Group' => 'Mass', 'Unit Name' => 'Gram', 'AllowPrefix' => true),
			'sg' => array('Group' => 'Mass', 'Unit Name' => 'Slug', 'AllowPrefix' => false),
			'lbm' => array('Group' => 'Mass', 'Unit Name' => 'Pound mass (avoirdupois)', 'AllowPrefix' => false),
			'u' => array('Group' => 'Mass', 'Unit Name' => 'U (atomic mass unit)', 'AllowPrefix' => true),
			'ozm' => array('Group' => 'Mass', 'Unit Name' => 'Ounce mass (avoirdupois)', 'AllowPrefix' => false),
			'm' => array('Group' => 'Distance', 'Unit Name' => 'Meter', 'AllowPrefix' => true),
			'mi' => array('Group' => 'Distance', 'Unit Name' => 'Statute mile', 'AllowPrefix' => false),
			'Nmi' => array('Group' => 'Distance', 'Unit Name' => 'Nautical mile', 'AllowPrefix' => false),
			'in' => array('Group' => 'Distance', 'Unit Name' => 'Inch', 'AllowPrefix' => false),
			'ft' => array('Group' => 'Distance', 'Unit Name' => 'Foot', 'AllowPrefix' => false),
			'yd' => array('Group' => 'Distance', 'Unit Name' => 'Yard', 'AllowPrefix' => false),
			'ang' => array('Group' => 'Distance', 'Unit Name' => 'Angstrom', 'AllowPrefix' => true),
			'Pica' => array('Group' => 'Distance', 'Unit Name' => 'Pica (1/72 in)', 'AllowPrefix' => false),
			'yr' => array('Group' => 'Time', 'Unit Name' => 'Year', 'AllowPrefix' => false),
			'day' => array('Group' => 'Time', 'Unit Name' => 'Day', 'AllowPrefix' => false),
			'hr' => array('Group' => 'Time', 'Unit Name' => 'Hour', 'AllowPrefix' => false),
			'mn' => array('Group' => 'Time', 'Unit Name' => 'Minute', 'AllowPrefix' => false),
			'sec' => array('Group' => 'Time', 'Unit Name' => 'Second', 'AllowPrefix' => true),
			'Pa' => array('Group' => 'Pressure', 'Unit Name' => 'Pascal', 'AllowPrefix' => true),
			'p' => array('Group' => 'Pressure', 'Unit Name' => 'Pascal', 'AllowPrefix' => true),
			'atm' => array('Group' => 'Pressure', 'Unit Name' => 'Atmosphere', 'AllowPrefix' => true),
			'at' => array('Group' => 'Pressure', 'Unit Name' => 'Atmosphere', 'AllowPrefix' => true),
			'mmHg' => array('Group' => 'Pressure', 'Unit Name' => 'mm of Mercury', 'AllowPrefix' => true),
			'N' => array('Group' => 'Force', 'Unit Name' => 'Newton', 'AllowPrefix' => true),
			'dyn' => array('Group' => 'Force', 'Unit Name' => 'Dyne', 'AllowPrefix' => true),
			'dy' => array('Group' => 'Force', 'Unit Name' => 'Dyne', 'AllowPrefix' => true),
			'lbf' => array('Group' => 'Force', 'Unit Name' => 'Pound force', 'AllowPrefix' => false),
			'J' => array('Group' => 'Energy', 'Unit Name' => 'Joule', 'AllowPrefix' => true),
			'e' => array('Group' => 'Energy', 'Unit Name' => 'Erg', 'AllowPrefix' => true),
			'c' => array('Group' => 'Energy', 'Unit Name' => 'Thermodynamic calorie', 'AllowPrefix' => true),
			'cal' => array('Group' => 'Energy', 'Unit Name' => 'IT calorie', 'AllowPrefix' => true),
			'eV' => array('Group' => 'Energy', 'Unit Name' => 'Electron volt', 'AllowPrefix' => true),
			'ev' => array('Group' => 'Energy', 'Unit Name' => 'Electron volt', 'AllowPrefix' => true),
			'HPh' => array('Group' => 'Energy', 'Unit Name' => 'Horsepower-hour', 'AllowPrefix' => false),
			'hh' => array('Group' => 'Energy', 'Unit Name' => 'Horsepower-hour', 'AllowPrefix' => false),
			'Wh' => array('Group' => 'Energy', 'Unit Name' => 'Watt-hour', 'AllowPrefix' => true),
			'wh' => array('Group' => 'Energy', 'Unit Name' => 'Watt-hour', 'AllowPrefix' => true),
			'flb' => array('Group' => 'Energy', 'Unit Name' => 'Foot-pound', 'AllowPrefix' => false),
			'BTU' => array('Group' => 'Energy', 'Unit Name' => 'BTU', 'AllowPrefix' => false),
			'btu' => array('Group' => 'Energy', 'Unit Name' => 'BTU', 'AllowPrefix' => false),
			'HP' => array('Group' => 'Power', 'Unit Name' => 'Horsepower', 'AllowPrefix' => false),
			'h' => array('Group' => 'Power', 'Unit Name' => 'Horsepower', 'AllowPrefix' => false),
			'W' => array('Group' => 'Power', 'Unit Name' => 'Watt', 'AllowPrefix' => true),
			'w' => array('Group' => 'Power', 'Unit Name' => 'Watt', 'AllowPrefix' => true),
			'T' => array('Group' => 'Magnetism', 'Unit Name' => 'Tesla', 'AllowPrefix' => true),
			'ga' => array('Group' => 'Magnetism', 'Unit Name' => 'Gauss', 'AllowPrefix' => true),
			'C' => array('Group' => 'Temperature', 'Unit Name' => 'Celsius', 'AllowPrefix' => false),
			'cel' => array('Group' => 'Temperature', 'Unit Name' => 'Celsius', 'AllowPrefix' => false),
			'F' => array('Group' => 'Temperature', 'Unit Name' => 'Fahrenheit', 'AllowPrefix' => false),
			'fah' => array('Group' => 'Temperature', 'Unit Name' => 'Fahrenheit', 'AllowPrefix' => false),
			'K' => array('Group' => 'Temperature', 'Unit Name' => 'Kelvin', 'AllowPrefix' => false),
			'kel' => array('Group' => 'Temperature', 'Unit Name' => 'Kelvin', 'AllowPrefix' => false),
			'tsp' => array('Group' => 'Liquid', 'Unit Name' => 'Teaspoon', 'AllowPrefix' => false),
			'tbs' => array('Group' => 'Liquid', 'Unit Name' => 'Tablespoon', 'AllowPrefix' => false),
			'oz' => array('Group' => 'Liquid', 'Unit Name' => 'Fluid Ounce', 'AllowPrefix' => false),
			'cup' => array('Group' => 'Liquid', 'Unit Name' => 'Cup', 'AllowPrefix' => false),
			'pt' => array('Group' => 'Liquid', 'Unit Name' => 'U.S. Pint', 'AllowPrefix' => false),
			'us_pt' => array('Group' => 'Liquid', 'Unit Name' => 'U.S. Pint', 'AllowPrefix' => false),
			'uk_pt' => array('Group' => 'Liquid', 'Unit Name' => 'U.K. Pint', 'AllowPrefix' => false),
			'qt' => array('Group' => 'Liquid', 'Unit Name' => 'Quart', 'AllowPrefix' => false),
			'gal' => array('Group' => 'Liquid', 'Unit Name' => 'Gallon', 'AllowPrefix' => false),
			'l' => array('Group' => 'Liquid', 'Unit Name' => 'Litre', 'AllowPrefix' => true),
			'lt' => array('Group' => 'Liquid', 'Unit Name' => 'Litre', 'AllowPrefix' => true)
	);

	/**
	 * Details of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM()
	 *
	 * @var mixed[]
	 */
	private static $_conversionMultipliers = array(
			'Y' => array('multiplier' => 1E24, 'name' => 'yotta'),
			'Z' => array('multiplier' => 1E21, 'name' => 'zetta'),
			'E' => array('multiplier' => 1E18, 'name' => 'exa'),
			'P' => array('multiplier' => 1E15, 'name' => 'peta'),
			'T' => array('multiplier' => 1E12, 'name' => 'tera'),
			'G' => array('multiplier' => 1E9, 'name' => 'giga'),
			'M' => array('multiplier' => 1E6, 'name' => 'mega'),
			'k' => array('multiplier' => 1E3, 'name' => 'kilo'),
			'h' => array('multiplier' => 1E2, 'name' => 'hecto'),
			'e' => array('multiplier' => 1E1, 'name' => 'deka'),
			'd' => array('multiplier' => 1E-1, 'name' => 'deci'),
			'c' => array('multiplier' => 1E-2, 'name' => 'centi'),
			'm' => array('multiplier' => 1E-3, 'name' => 'milli'),
			'u' => array('multiplier' => 1E-6, 'name' => 'micro'),
			'n' => array('multiplier' => 1E-9, 'name' => 'nano'),
			'p' => array('multiplier' => 1E-12, 'name' => 'pico'),
			'f' => array('multiplier' => 1E-15, 'name' => 'femto'),
			'a' => array('multiplier' => 1E-18, 'name' => 'atto'),
			'z' => array('multiplier' => 1E-21, 'name' => 'zepto'),
			'y' => array('multiplier' => 1E-24, 'name' => 'yocto')
	);

	/**
	 * Details of the Units of measure conversion factors, organised by group
	 *
	 * @var mixed[]
	 */
	private static $_unitConversions = array(
			'Mass' => array(
					'g' => array(
							'g' => 1.0,
							'sg' => 6.85220500053478E-05,
							'lbm' => 2.20462291469134E-03,
							'u' => 6.02217000000000E+23,
							'ozm' => 3.52739718003627E-02
					),
					'sg' => array(
							'g' => 1.45938424189287E+04,
							'sg' => 1.0,
							'lbm' => 3.21739194101647E+01,
							'u' => 8.78866000000000E+27,
							'ozm' => 5.14782785944229E+02
					),
					'lbm' => array(
							'g' => 4.5359230974881148E+02,
							'sg' => 3.10810749306493E-02,
							'lbm' => 1.0,
							'u' => 2.73161000000000E+26,
							'ozm' => 1.60000023429410E+01
					),
					'u' => array(
							'g' => 1.66053100460465E-24,
							'sg' => 1.13782988532950E-28,
							'lbm' => 3.66084470330684E-27,
							'u' => 1.0,
							'ozm' => 5.85735238300524E-26
					),
					'ozm' => array(
							'g' => 2.83495152079732E+01,
							'sg' => 1.94256689870811E-03,
							'lbm' => 6.24999908478882E-02,
							'u' => 1.70725600000000E+25,
							'ozm' => 1.0
					)
			),
			'Distance' => array(
					'm' => array(
							'm' => 1.0,
							'mi' => 6.21371192237334E-04,
							'Nmi' => 5.39956803455724E-04,
							'in' => 3.93700787401575E+01,
							'ft' => 3.28083989501312E+00,
							'yd' => 1.09361329797891E+00,
							'ang' => 1.00000000000000E+10,
							'Pica' => 2.83464566929116E+03
					),
					'mi' => array(
							'm' => 1.60934400000000E+03,
							'mi' => 1.0,
							'Nmi' => 8.68976241900648E-01,
							'in' => 6.33600000000000E+04,
							'ft' => 5.28000000000000E+03,
							'yd' => 1.76000000000000E+03,
							'ang' => 1.60934400000000E+13,
							'Pica' => 4.56191999999971E+06
					),
					'Nmi' => array(
							'm' => 1.85200000000000E+03,
							'mi' => 1.15077944802354E+00,
							'Nmi' => 1.0,
							'in' => 7.29133858267717E+04,
							'ft' => 6.07611548556430E+03,
							'yd' => 2.02537182785694E+03,
							'ang' => 1.85200000000000E+13,
							'Pica' => 5.24976377952723E+06
					),
					'in' => array(
							'm' => 2.54000000000000E-02,
							'mi' => 1.57828282828283E-05,
							'Nmi' => 1.37149028077754E-05,
							'in' => 1.0,
							'ft' => 8.33333333333333E-02,
							'yd' => 2.77777777686643E-02,
							'ang' => 2.54000000000000E+08,
							'Pica' => 7.19999999999955E+01
					),
					'ft' => array(
							'm' => 3.04800000000000E-01,
							'mi' => 1.89393939393939E-04,
							'Nmi' => 1.64578833693305E-04,
							'in' => 1.20000000000000E+01,
							'ft' => 1.0,
							'yd' => 3.33333333223972E-01,
							'ang' => 3.04800000000000E+09,
							'Pica' => 8.63999999999946E+02
					),
					'yd' => array(
							'm' => 9.14400000300000E-01,
							'mi' => 5.68181818368230E-04,
							'Nmi' => 4.93736501241901E-04,
							'in' => 3.60000000118110E+01,
							'ft' => 3.00000000000000E+00,
							'yd' => 1.0,
							'ang' => 9.14400000300000E+09,
							'Pica' => 2.59200000085023E+03
					),
					'ang' => array(
							'm' => 1.00000000000000E-10,
							'mi' => 6.21371192237334E-14,
							'Nmi' => 5.39956803455724E-14,
							'in' => 3.93700787401575E-09,
							'ft' => 3.28083989501312E-10,
							'yd' => 1.09361329797891E-10,
							'ang' => 1.0,
							'Pica' => 2.83464566929116E-07
					),
					'Pica' => array(
							'm' => 3.52777777777800E-04,
							'mi' => 2.19205948372629E-07,
							'Nmi' => 1.90484761219114E-07,
							'in' => 1.38888888888898E-02,
							'ft' => 1.15740740740748E-03,
							'yd' => 3.85802469009251E-04,
							'ang' => 3.52777777777800E+06,
							'Pica' => 1.0
					)
			),
			'Time' => array(
					'yr' => array(
							'yr' => 1.0,
							'day' => 365.25,
							'hr' => 8766.0,
							'mn' => 525960.0,
							'sec' => 31557600.0
					),
					'day' => array(
							'yr' => 2.73785078713210E-03,
							'day' => 1.0,
							'hr' => 24.0,
							'mn' => 1440.0,
							'sec' => 86400.0
					),
					'hr' => array(
							'yr' => 1.14077116130504E-04,
							'day' => 4.16666666666667E-02,
							'hr' => 1.0,
							'mn' => 60.0,
							'sec' => 3600.0
					),
					'mn' => array(
							'yr' => 1.90128526884174E-06,
							'day' => 6.94444444444444E-04,
							'hr' => 1.66666666666667E-02,
							'mn' => 1.0,
							'sec' => 60.0
					),
					'sec' => array(
							'yr' => 3.16880878140289E-08,
							'day' => 1.15740740740741E-05,
							'hr' => 2.77777777777778E-04,
							'mn' => 1.66666666666667E-02,
							'sec' => 1.0
					)
			),
			'Pressure' => array(
					'Pa' => array(
							'Pa' => 1.0,
							'p' => 1.0,
							'atm' => 9.86923299998193E-06,
							'at' => 9.86923299998193E-06,
							'mmHg' => 7.50061707998627E-03
					),
					'p' => array(
							'Pa' => 1.0,
							'p' => 1.0,
							'atm' => 9.86923299998193E-06,
							'at' => 9.86923299998193E-06,
							'mmHg' => 7.50061707998627E-03
					),
					'atm' => array(
							'Pa' => 1.01324996583000E+05,
							'p' => 1.01324996583000E+05,
							'atm' => 1.0,
							'at' => 1.0,
							'mmHg' => 760.0
					),
					'at' => array(
							'Pa' => 1.01324996583000E+05,
							'p' => 1.01324996583000E+05,
							'atm' => 1.0,
							'at' => 1.0,
							'mmHg' => 760.0
					),
					'mmHg' => array(
							'Pa' => 1.33322363925000E+02,
							'p' => 1.33322363925000E+02,
							'atm' => 1.31578947368421E-03,
							'at' => 1.31578947368421E-03,
							'mmHg' => 1.0
					)
			),
			'Force' => array(
					'N' => array(
							'N' => 1.0,
							'dyn' => 1.0E+5,
							'dy' => 1.0E+5,
							'lbf' => 2.24808923655339E-01
					),
					'dyn' => array(
							'N' => 1.0E-5,
							'dyn' => 1.0,
							'dy' => 1.0,
							'lbf' => 2.24808923655339E-06
					),
					'dy' => array(
							'N' => 1.0E-5,
							'dyn' => 1.0,
							'dy' => 1.0,
							'lbf' => 2.24808923655339E-06
					),
					'lbf' => array(
							'N' => 4.448222,
							'dyn' => 4.448222E+5,
							'dy' => 4.448222E+5,
							'lbf' => 1.0
					)
			),
			'Energy' => array(
					'J' => array(
							'J' => 1.0,
							'e' => 9.99999519343231E+06,
							'c' => 2.39006249473467E-01,
							'cal' => 2.38846190642017E-01,
							'eV' => 6.24145700000000E+18,
							'ev' => 6.24145700000000E+18,
							'HPh' => 3.72506430801000E-07,
							'hh' => 3.72506430801000E-07,
							'Wh' => 2.77777916238711E-04,
							'wh' => 2.77777916238711E-04,
							'flb' => 2.37304222192651E+01,
							'BTU' => 9.47815067349015E-04,
							'btu' => 9.47815067349015E-04
					),
					'e' => array(
							'J' => 1.00000048065700E-07,
							'e' => 1.0,
							'c' => 2.39006364353494E-08,
							'cal' => 2.38846305445111E-08,
							'eV' => 6.24146000000000E+11,
							'ev' => 6.24146000000000E+11,
							'HPh' => 3.72506609848824E-14,
							'hh' => 3.72506609848824E-14,
							'Wh' => 2.77778049754611E-11,
							'wh' => 2.77778049754611E-11,
							'flb' => 2.37304336254586E-06,
							'BTU' => 9.47815522922962E-11,
							'btu' => 9.47815522922962E-11
					),
					'c' => array(
							'J' => 4.18399101363672E+00,
							'e' => 4.18398900257312E+07,
							'c' => 1.0,
							'cal' => 9.99330315287563E-01,
							'eV' => 2.61142000000000E+19,
							'ev' => 2.61142000000000E+19,
							'HPh' => 1.55856355899327E-06,
							'hh' => 1.55856355899327E-06,
							'Wh' => 1.16222030532950E-03,
							'wh' => 1.16222030532950E-03,
							'flb' => 9.92878733152102E+01,
							'BTU' => 3.96564972437776E-03,
							'btu' => 3.96564972437776E-03
					),
					'cal' => array(
							'J' => 4.18679484613929E+00,
							'e' => 4.18679283372801E+07,
							'c' => 1.00067013349059E+00,
							'cal' => 1.0,
							'eV' => 2.61317000000000E+19,
							'ev' => 2.61317000000000E+19,
							'HPh' => 1.55960800463137E-06,
							'hh' => 1.55960800463137E-06,
							'Wh' => 1.16299914807955E-03,
							'wh' => 1.16299914807955E-03,
							'flb' => 9.93544094443283E+01,
							'BTU' => 3.96830723907002E-03,
							'btu' => 3.96830723907002E-03
					),
					'eV' => array(
							'J' => 1.60219000146921E-19,
							'e' => 1.60218923136574E-12,
							'c' => 3.82933423195043E-20,
							'cal' => 3.82676978535648E-20,
							'eV' => 1.0,
							'ev' => 1.0,
							'HPh' => 5.96826078912344E-26,
							'hh' => 5.96826078912344E-26,
							'Wh' => 4.45053000026614E-23,
							'wh' => 4.45053000026614E-23,
							'flb' => 3.80206452103492E-18,
							'BTU' => 1.51857982414846E-22,
							'btu' => 1.51857982414846E-22
					),
					'ev' => array(
							'J' => 1.60219000146921E-19,
							'e' => 1.60218923136574E-12,
							'c' => 3.82933423195043E-20,
							'cal' => 3.82676978535648E-20,
							'eV' => 1.0,
							'ev' => 1.0,
							'HPh' => 5.96826078912344E-26,
							'hh' => 5.96826078912344E-26,
							'Wh' => 4.45053000026614E-23,
							'wh' => 4.45053000026614E-23,
							'flb' => 3.80206452103492E-18,
							'BTU' => 1.51857982414846E-22,
							'btu' => 1.51857982414846E-22
					),
					'HPh' => array(
							'J' => 2.68451741316170E+06,
							'e' => 2.68451612283024E+13,
							'c' => 6.41616438565991E+05,
							'cal' => 6.41186757845835E+05,
							'eV' => 1.67553000000000E+25,
							'ev' => 1.67553000000000E+25,
							'HPh' => 1.0,
							'hh' => 1.0,
							'Wh' => 7.45699653134593E+02,
							'wh' => 7.45699653134593E+02,
							'flb' => 6.37047316692964E+07,
							'BTU' => 2.54442605275546E+03,
							'btu' => 2.54442605275546E+03
					),
					'hh' => array(
							'J' => 2.68451741316170E+06,
							'e' => 2.68451612283024E+13,
							'c' => 6.41616438565991E+05,
							'cal' => 6.41186757845835E+05,
							'eV' => 1.67553000000000E+25,
							'ev' => 1.67553000000000E+25,
							'HPh' => 1.0,
							'hh' => 1.0,
							'Wh' => 7.45699653134593E+02,
							'wh' => 7.45699653134593E+02,
							'flb' => 6.37047316692964E+07,
							'BTU' => 2.54442605275546E+03,
							'btu' => 2.54442605275546E+03
					),
					'Wh' => array(
							'J' => 3.59999820554720E+03,
							'e' => 3.59999647518369E+10,
							'c' => 8.60422069219046E+02,
							'cal' => 8.59845857713046E+02,
							'eV' => 2.24692340000000E+22,
							'ev' => 2.24692340000000E+22,
							'HPh' => 1.34102248243839E-03,
							'hh' => 1.34102248243839E-03,
							'Wh' => 1.0,
							'wh' => 1.0,
							'flb' => 8.54294774062316E+04,
							'BTU' => 3.41213254164705E+00,
							'btu' => 3.41213254164705E+00
					),
					'wh' => array(
							'J' => 3.59999820554720E+03,
							'e' => 3.59999647518369E+10,
							'c' => 8.60422069219046E+02,
							'cal' => 8.59845857713046E+02,
							'eV' => 2.24692340000000E+22,
							'ev' => 2.24692340000000E+22,
							'HPh' => 1.34102248243839E-03,
							'hh' => 1.34102248243839E-03,
							'Wh' => 1.0,
							'wh' => 1.0,
							'flb' => 8.54294774062316E+04,
							'BTU' => 3.41213254164705E+00,
							'btu' => 3.41213254164705E+00
					),
					'flb' => array(
							'J' => 4.21400003236424E-02,
							'e' => 4.21399800687660E+05,
							'c' => 1.00717234301644E-02,
							'cal' => 1.00649785509554E-02,
							'eV' => 2.63015000000000E+17,
							'ev' => 2.63015000000000E+17,
							'HPh' => 1.56974211145130E-08,
							'hh' => 1.56974211145130E-08,
							'Wh' => 1.17055614802000E-05,
							'wh' => 1.17055614802000E-05,
							'flb' => 1.0,
							'BTU' => 3.99409272448406E-05,
							'btu' => 3.99409272448406E-05
					),
					'BTU' => array(
							'J' => 1.05505813786749E+03,
							'e' => 1.05505763074665E+10,
							'c' => 2.52165488508168E+02,
							'cal' => 2.51996617135510E+02,
							'eV' => 6.58510000000000E+21,
							'ev' => 6.58510000000000E+21,
							'HPh' => 3.93015941224568E-04,
							'hh' => 3.93015941224568E-04,
							'Wh' => 2.93071851047526E-01,
							'wh' => 2.93071851047526E-01,
							'flb' => 2.50369750774671E+04,
							'BTU' => 1.0,
							'btu' => 1.0,
					),
					'btu' => array(
							'J' => 1.05505813786749E+03,
							'e' => 1.05505763074665E+10,
							'c' => 2.52165488508168E+02,
							'cal' => 2.51996617135510E+02,
							'eV' => 6.58510000000000E+21,
							'ev' => 6.58510000000000E+21,
							'HPh' => 3.93015941224568E-04,
							'hh' => 3.93015941224568E-04,
							'Wh' => 2.93071851047526E-01,
							'wh' => 2.93071851047526E-01,
							'flb' => 2.50369750774671E+04,
							'BTU' => 1.0,
							'btu' => 1.0,
					)
			),
			'Power' => array(
					'HP' => array(
							'HP' => 1.0,
							'h' => 1.0,
							'W' => 7.45701000000000E+02,
							'w' => 7.45701000000000E+02
					),
					'h' => array(
							'HP' => 1.0,
							'h' => 1.0,
							'W' => 7.45701000000000E+02,
							'w' => 7.45701000000000E+02
					),
					'W' => array(
							'HP' => 1.34102006031908E-03,
							'h' => 1.34102006031908E-03,
							'W' => 1.0,
							'w' => 1.0
					),
					'w' => array(
							'HP' => 1.34102006031908E-03,
							'h' => 1.34102006031908E-03,
							'W' => 1.0,
							'w' => 1.0
					)
			),
			'Magnetism' => array(
					'T' => array(
							'T' => 1.0,
							'ga' => 10000.0
					),
					'ga' => array(
							'T' => 0.0001,
							'ga' => 1.0
					)
			),
			'Liquid' => array(
					'tsp' => array(
							'tsp' => 1.0,
							'tbs' => 3.33333333333333E-01,
							'oz' => 1.66666666666667E-01,
							'cup' => 2.08333333333333E-02,
							'pt' => 1.04166666666667E-02,
							'us_pt' => 1.04166666666667E-02,
							'uk_pt' => 8.67558516821960E-03,
							'qt' => 5.20833333333333E-03,
							'gal' => 1.30208333333333E-03,
							'l' => 4.92999408400710E-03,
							'lt' => 4.92999408400710E-03
					),
					'tbs' => array(
							'tsp' => 3.00000000000000E+00,
							'tbs' => 1.0,
							'oz' => 5.00000000000000E-01,
							'cup' => 6.25000000000000E-02,
							'pt' => 3.12500000000000E-02,
							'us_pt' => 3.12500000000000E-02,
							'uk_pt' => 2.60267555046588E-02,
							'qt' => 1.56250000000000E-02,
							'gal' => 3.90625000000000E-03,
							'l' => 1.47899822520213E-02,
							'lt' => 1.47899822520213E-02
					),
					'oz' => array(
							'tsp' => 6.00000000000000E+00,
							'tbs' => 2.00000000000000E+00,
							'oz' => 1.0,
							'cup' => 1.25000000000000E-01,
							'pt' => 6.25000000000000E-02,
							'us_pt' => 6.25000000000000E-02,
							'uk_pt' => 5.20535110093176E-02,
							'qt' => 3.12500000000000E-02,
							'gal' => 7.81250000000000E-03,
							'l' => 2.95799645040426E-02,
							'lt' => 2.95799645040426E-02
					),
					'cup' => array(
							'tsp' => 4.80000000000000E+01,
							'tbs' => 1.60000000000000E+01,
							'oz' => 8.00000000000000E+00,
							'cup' => 1.0,
							'pt' => 5.00000000000000E-01,
							'us_pt' => 5.00000000000000E-01,
							'uk_pt' => 4.16428088074541E-01,
							'qt' => 2.50000000000000E-01,
							'gal' => 6.25000000000000E-02,
							'l' => 2.36639716032341E-01,
							'lt' => 2.36639716032341E-01
					),
					'pt' => array(
							'tsp' => 9.60000000000000E+01,
							'tbs' => 3.20000000000000E+01,
							'oz' => 1.60000000000000E+01,
							'cup' => 2.00000000000000E+00,
							'pt' => 1.0,
							'us_pt' => 1.0,
							'uk_pt' => 8.32856176149081E-01,
							'qt' => 5.00000000000000E-01,
							'gal' => 1.25000000000000E-01,
							'l' => 4.73279432064682E-01,
							'lt' => 4.73279432064682E-01
					),
					'us_pt' => array(
							'tsp' => 9.60000000000000E+01,
							'tbs' => 3.20000000000000E+01,
							'oz' => 1.60000000000000E+01,
							'cup' => 2.00000000000000E+00,
							'pt' => 1.0,
							'us_pt' => 1.0,
							'uk_pt' => 8.32856176149081E-01,
							'qt' => 5.00000000000000E-01,
							'gal' => 1.25000000000000E-01,
							'l' => 4.73279432064682E-01,
							'lt' => 4.73279432064682E-01
					),
					'uk_pt' => array(
							'tsp' => 1.15266000000000E+02,
							'tbs' => 3.84220000000000E+01,
							'oz' => 1.92110000000000E+01,
							'cup' => 2.40137500000000E+00,
							'pt' => 1.20068750000000E+00,
							'us_pt' => 1.20068750000000E+00,
							'uk_pt' => 1.0,
							'qt' => 6.00343750000000E-01,
							'gal' => 1.50085937500000E-01,
							'l' => 5.68260698087162E-01,
							'lt' => 5.68260698087162E-01
					),
					'qt' => array(
							'tsp' => 1.92000000000000E+02,
							'tbs' => 6.40000000000000E+01,
							'oz' => 3.20000000000000E+01,
							'cup' => 4.00000000000000E+00,
							'pt' => 2.00000000000000E+00,
							'us_pt' => 2.00000000000000E+00,
							'uk_pt' => 1.66571235229816E+00,
							'qt' => 1.0,
							'gal' => 2.50000000000000E-01,
							'l' => 9.46558864129363E-01,
							'lt' => 9.46558864129363E-01
					),
					'gal' => array(
							'tsp' => 7.68000000000000E+02,
							'tbs' => 2.56000000000000E+02,
							'oz' => 1.28000000000000E+02,
							'cup' => 1.60000000000000E+01,
							'pt' => 8.00000000000000E+00,
							'us_pt' => 8.00000000000000E+00,
							'uk_pt' => 6.66284940919265E+00,
							'qt' => 4.00000000000000E+00,
							'gal' => 1.0,
							'l' => 3.78623545651745E+00,
							'lt' => 3.78623545651745E+00
					),
					'l' => array(
							'tsp' => 2.02840000000000E+02,
							'tbs' => 6.76133333333333E+01,
							'oz' => 3.38066666666667E+01,
							'cup' => 4.22583333333333E+00,
							'pt' => 2.11291666666667E+00,
							'us_pt' => 2.11291666666667E+00,
							'uk_pt' => 1.75975569552166E+00,
							'qt' => 1.05645833333333E+00,
							'gal' => 2.64114583333333E-01,
							'l' => 1.0,
							'lt' => 1.0
					),
					'lt' => array(
							'tsp' => 2.02840000000000E+02,
							'tbs' => 6.76133333333333E+01,
							'oz' => 3.38066666666667E+01,
							'cup' => 4.22583333333333E+00,
							'pt' => 2.11291666666667E+00,
							'us_pt' => 2.11291666666667E+00,
							'uk_pt' => 1.75975569552166E+00,
							'qt' => 1.05645833333333E+00,
							'gal' => 2.64114583333333E-01,
							'l' => 1.0,
							'lt' => 1.0
					)
			)
	);


	/**
	 * _parseComplex
	 *
	 * Parses a complex number into its real and imaginary parts, and an I or J suffix
	 *
	 * @param    string $complexNumber The complex number
	 *
	 * @return    string[]    Indexed on "real", "imaginary" and "suffix"
	 */
	public static function _parseComplex($complexNumber) {
		$workString = (string)$complexNumber;

		$realNumber = $imaginary = 0;
		//	Extract the suffix, if there is one
		$suffix = substr($workString, -1);
		if (!is_numeric($suffix))
		{
			$workString = substr($workString, 0, -1);
		}
		else
		{
			$suffix = '';
		}

		//	Split the input into its Real and Imaginary components
		$leadingSign = 0;
		if (strlen($workString) > 0)
		{
			$leadingSign = (($workString{0} == '+') || ($workString{0} == '-')) ? 1 : 0;
		}
		$power = '';
		$realNumber = strtok($workString, '+-');
		if (strtoupper(substr($realNumber, -1)) == 'E')
		{
			$power = strtok('+-');
			++$leadingSign;
		}

		$realNumber = substr($workString, 0, strlen($realNumber) + strlen($power) + $leadingSign);

		if ($suffix != '')
		{
			$imaginary = substr($workString, strlen($realNumber));

			if (($imaginary == '') && (($realNumber == '') || ($realNumber == '+') || ($realNumber == '-')))
			{
				$imaginary = $realNumber . '1';
				$realNumber = '0';
			}
			else if ($imaginary == '')
			{
				$imaginary = $realNumber;
				$realNumber = '0';
			}
			elseif (($imaginary == '+') || ($imaginary == '-'))
			{
				$imaginary .= '1';
			}
		}

		return array(
				'real' => $realNumber,
				'imaginary' => $imaginary,
				'suffix' => $suffix
		);
	} //	function _parseComplex()


	/**
	 * Cleans the leading characters in a complex number string
	 *
	 * @param    string $complexNumber The complex number to clean
	 *
	 * @return    string        The "cleaned" complex number
	 */
	private static function _cleanComplex($complexNumber) {
		if ($complexNumber{0} == '+')
			$complexNumber = substr($complexNumber, 1);
		if ($complexNumber{0} == '0')
			$complexNumber = substr($complexNumber, 1);
		if ($complexNumber{0} == '.')
			$complexNumber = '0' . $complexNumber;
		if ($complexNumber{0} == '+')
			$complexNumber = substr($complexNumber, 1);

		return $complexNumber;
	}

	/**
	 * Formats a number base string value with leading zeroes
	 *
	 * @param    string  $xVal   The "number" to pad
	 * @param    integer $places The length that we want to pad this value
	 *
	 * @return    string        The padded "number"
	 */
	private static function _nbrConversionFormat($xVal, $places) {
		if (!is_null($places))
		{
			if (strlen($xVal) <= $places)
			{
				return substr(str_pad($xVal, $places, '0', STR_PAD_LEFT), -10);
			}
			else
			{
				return PHPExcel_Calculation_Functions::NaN();
			}
		}

		return substr($xVal, -10);
	} //	function _nbrConversionFormat()

	/**
	 *    BESSELI
	 *
	 *    Returns the modified Bessel function In(x), which is equivalent to the Bessel function evaluated
	 *        for purely imaginary arguments
	 *
	 *    Excel Function:
	 *        BESSELI(x,ord)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    float   $x           The value at which to evaluate the function.
	 *                                If x is nonnumeric, BESSELI returns the #VALUE! error value.
	 * @param    integer $ord         The order of the Bessel function.
	 *                                If ord is not an integer, it is truncated.
	 *                                If $ord is nonnumeric, BESSELI returns the #VALUE! error value.
	 *                                If $ord < 0, BESSELI returns the #NUM! error value.
	 *
	 * @return    float
	 *
	 */
	public static function BESSELI($x, $ord) {
		$x = (is_null($x)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$ord = (is_null($ord)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($ord);

		if ((is_numeric($x)) && (is_numeric($ord)))
		{
			$ord = floor($ord);
			if ($ord < 0)
			{
				return PHPExcel_Calculation_Functions::NaN();
			}

			if (abs($x) <= 30)
			{
				$fResult = $fTerm = pow($x / 2, $ord) / PHPExcel_Calculation_MathTrig::FACT($ord);
				$ordK = 1;
				$fSqrX = ($x * $x) / 4;
				do
				{
					$fTerm *= $fSqrX;
					$fTerm /= ($ordK * ($ordK + $ord));
					$fResult += $fTerm;
				} while ((abs($fTerm) > 1e-12) && (++$ordK < 100));
			}
			else
			{
				$f_2_PI = 2 * M_PI;

				$fXAbs = abs($x);
				$fResult = exp($fXAbs) / sqrt($f_2_PI * $fXAbs);
				if (($ord & 1) && ($x < 0))
				{
					$fResult = -$fResult;
				}
			}

			return (is_nan($fResult)) ? PHPExcel_Calculation_Functions::NaN() : $fResult;
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function BESSELI()


	/**
	 *    BESSELJ
	 *
	 *    Returns the Bessel function
	 *
	 *    Excel Function:
	 *        BESSELJ(x,ord)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    float   $x           The value at which to evaluate the function.
	 *                                If x is nonnumeric, BESSELJ returns the #VALUE! error value.
	 * @param    integer $ord         The order of the Bessel function. If n is not an integer, it is truncated.
	 *                                If $ord is nonnumeric, BESSELJ returns the #VALUE! error value.
	 *                                If $ord < 0, BESSELJ returns the #NUM! error value.
	 *
	 * @return    float
	 *
	 */
	public static function BESSELJ($x, $ord) {
		$x = (is_null($x)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$ord = (is_null($ord)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($ord);

		if ((is_numeric($x)) && (is_numeric($ord)))
		{
			$ord = floor($ord);
			if ($ord < 0)
			{
				return PHPExcel_Calculation_Functions::NaN();
			}

			$fResult = 0;
			if (abs($x) <= 30)
			{
				$fResult = $fTerm = pow($x / 2, $ord) / PHPExcel_Calculation_MathTrig::FACT($ord);
				$ordK = 1;
				$fSqrX = ($x * $x) / -4;
				do
				{
					$fTerm *= $fSqrX;
					$fTerm /= ($ordK * ($ordK + $ord));
					$fResult += $fTerm;
				} while ((abs($fTerm) > 1e-12) && (++$ordK < 100));
			}
			else
			{
				$f_PI_DIV_2 = M_PI / 2;
				$f_PI_DIV_4 = M_PI / 4;

				$fXAbs = abs($x);
				$fResult = sqrt(M_2DIVPI / $fXAbs) * cos($fXAbs - $ord * $f_PI_DIV_2 - $f_PI_DIV_4);
				if (($ord & 1) && ($x < 0))
				{
					$fResult = -$fResult;
				}
			}

			return (is_nan($fResult)) ? PHPExcel_Calculation_Functions::NaN() : $fResult;
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function BESSELJ()


	private static function _Besselk0($fNum) {
		if ($fNum <= 2)
		{
			$fNum2 = $fNum * 0.5;
			$y = ($fNum2 * $fNum2);
			$fRet = -log($fNum2) * self::BESSELI($fNum, 0) + (-0.57721566 + $y * (0.42278420 + $y * (0.23069756 + $y * (0.3488590e-1 + $y * (0.262698e-2 + $y * (0.10750e-3 + $y * 0.74e-5))))));
		}
		else
		{
			$y = 2 / $fNum;
			$fRet = exp(-$fNum) / sqrt($fNum) * (1.25331414 + $y * (-0.7832358e-1 + $y * (0.2189568e-1 + $y * (-0.1062446e-1 + $y * (0.587872e-2 + $y * (-0.251540e-2 + $y * 0.53208e-3))))));
		}

		return $fRet;
	} //	function _Besselk0()


	private static function _Besselk1($fNum) {
		if ($fNum <= 2)
		{
			$fNum2 = $fNum * 0.5;
			$y = ($fNum2 * $fNum2);
			$fRet = log($fNum2) * self::BESSELI($fNum, 1) + (1 + $y * (0.15443144 + $y * (-0.67278579 + $y * (-0.18156897 + $y * (-0.1919402e-1 + $y * (-0.110404e-2 + $y * (-0.4686e-4))))))) / $fNum;
		}
		else
		{
			$y = 2 / $fNum;
			$fRet = exp(-$fNum) / sqrt($fNum) * (1.25331414 + $y * (0.23498619 + $y * (-0.3655620e-1 + $y * (0.1504268e-1 + $y * (-0.780353e-2 + $y * (0.325614e-2 + $y * (-0.68245e-3)))))));
		}

		return $fRet;
	} //	function _Besselk1()


	/**
	 *    BESSELK
	 *
	 *    Returns the modified Bessel function Kn(x), which is equivalent to the Bessel functions evaluated
	 *        for purely imaginary arguments.
	 *
	 *    Excel Function:
	 *        BESSELK(x,ord)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    float   $x           The value at which to evaluate the function.
	 *                                If x is nonnumeric, BESSELK returns the #VALUE! error value.
	 * @param    integer $ord         The order of the Bessel function. If n is not an integer, it is truncated.
	 *                                If $ord is nonnumeric, BESSELK returns the #VALUE! error value.
	 *                                If $ord < 0, BESSELK returns the #NUM! error value.
	 *
	 * @return    float
	 *
	 */
	public static function BESSELK($x, $ord) {
		$x = (is_null($x)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$ord = (is_null($ord)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($ord);

		if ((is_numeric($x)) && (is_numeric($ord)))
		{
			if (($ord < 0) || ($x == 0.0))
			{
				return PHPExcel_Calculation_Functions::NaN();
			}

			switch (floor($ord))
			{
				case 0 :
					return self::_Besselk0($x);
					break;
				case 1 :
					return self::_Besselk1($x);
					break;
				default :
					$fTox = 2 / $x;
					$fBkm = self::_Besselk0($x);
					$fBk = self::_Besselk1($x);
					for ($n = 1; $n < $ord; ++$n)
					{
						$fBkp = $fBkm + $n * $fTox * $fBk;
						$fBkm = $fBk;
						$fBk = $fBkp;
					}
			}

			return (is_nan($fBk)) ? PHPExcel_Calculation_Functions::NaN() : $fBk;
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function BESSELK()


	private static function _Bessely0($fNum) {
		if ($fNum < 8.0)
		{
			$y = ($fNum * $fNum);
			$f1 = -2957821389.0 + $y * (7062834065.0 + $y * (-512359803.6 + $y * (10879881.29 + $y * (-86327.92757 + $y * 228.4622733))));
			$f2 = 40076544269.0 + $y * (745249964.8 + $y * (7189466.438 + $y * (47447.26470 + $y * (226.1030244 + $y))));
			$fRet = $f1 / $f2 + 0.636619772 * self::BESSELJ($fNum, 0) * log($fNum);
		}
		else
		{
			$z = 8.0 / $fNum;
			$y = ($z * $z);
			$xx = $fNum - 0.785398164;
			$f1 = 1 + $y * (-0.1098628627e-2 + $y * (0.2734510407e-4 + $y * (-0.2073370639e-5 + $y * 0.2093887211e-6)));
			$f2 = -0.1562499995e-1 + $y * (0.1430488765e-3 + $y * (-0.6911147651e-5 + $y * (0.7621095161e-6 + $y * (-0.934945152e-7))));
			$fRet = sqrt(0.636619772 / $fNum) * (sin($xx) * $f1 + $z * cos($xx) * $f2);
		}

		return $fRet;
	} //	function _Bessely0()


	private static function _Bessely1($fNum) {
		if ($fNum < 8.0)
		{
			$y = ($fNum * $fNum);
			$f1 = $fNum * (-0.4900604943e13 + $y * (0.1275274390e13 + $y * (-0.5153438139e11 + $y * (0.7349264551e9 + $y * (-0.4237922726e7 + $y * 0.8511937935e4)))));
			$f2 = 0.2499580570e14 + $y * (0.4244419664e12 + $y * (0.3733650367e10 + $y * (0.2245904002e8 + $y * (0.1020426050e6 + $y * (0.3549632885e3 + $y)))));
			$fRet = $f1 / $f2 + 0.636619772 * (self::BESSELJ($fNum, 1) * log($fNum) - 1 / $fNum);
		}
		else
		{
			$fRet = sqrt(0.636619772 / $fNum) * sin($fNum - 2.356194491);
		}

		return $fRet;
	} //	function _Bessely1()


	/**
	 *    BESSELY
	 *
	 *    Returns the Bessel function, which is also called the Weber function or the Neumann function.
	 *
	 *    Excel Function:
	 *        BESSELY(x,ord)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    float   $x           The value at which to evaluate the function.
	 *                                If x is nonnumeric, BESSELK returns the #VALUE! error value.
	 * @param    integer $ord         The order of the Bessel function. If n is not an integer, it is truncated.
	 *                                If $ord is nonnumeric, BESSELK returns the #VALUE! error value.
	 *                                If $ord < 0, BESSELK returns the #NUM! error value.
	 *
	 * @return    float
	 */
	public static function BESSELY($x, $ord) {
		$x = (is_null($x)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$ord = (is_null($ord)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($ord);

		if ((is_numeric($x)) && (is_numeric($ord)))
		{
			if (($ord < 0) || ($x == 0.0))
			{
				return PHPExcel_Calculation_Functions::NaN();
			}

			switch (floor($ord))
			{
				case 0 :
					return self::_Bessely0($x);
					break;
				case 1 :
					return self::_Bessely1($x);
					break;
				default:
					$fTox = 2 / $x;
					$fBym = self::_Bessely0($x);
					$fBy = self::_Bessely1($x);
					for ($n = 1; $n < $ord; ++$n)
					{
						$fByp = $n * $fTox * $fBy - $fBym;
						$fBym = $fBy;
						$fBy = $fByp;
					}
			}

			return (is_nan($fBy)) ? PHPExcel_Calculation_Functions::NaN() : $fBy;
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function BESSELY()


	/**
	 * BINTODEC
	 *
	 * Return a binary value as decimal.
	 *
	 * Excel Function:
	 *        BIN2DEC(x)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string $x            The binary number (as a string) that you want to convert. The number
	 *                                cannot contain more than 10 characters (10 bits). The most significant
	 *                                bit of number is the sign bit. The remaining 9 bits are magnitude bits.
	 *                                Negative numbers are represented using two's-complement notation.
	 *                                If number is not a valid binary number, or if number contains more than
	 *                                10 characters (10 bits), BIN2DEC returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function BINTODEC($x) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);

		if (is_bool($x))
		{
			if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)
			{
				$x = (int)$x;
			}
			else
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}
		}
		if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_GNUMERIC)
		{
			$x = floor($x);
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[01]/', $x, $out))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		if (strlen($x) > 10)
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		elseif (strlen($x) == 10)
		{
			//	Two's Complement
			$x = substr($x, -9);

			return '-' . (512 - bindec($x));
		}

		return bindec($x);
	} //	function BINTODEC()


	/**
	 * BINTOHEX
	 *
	 * Return a binary value as hex.
	 *
	 * Excel Function:
	 *        BIN2HEX(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x           The binary number (as a string) that you want to convert. The number
	 *                                cannot contain more than 10 characters (10 bits). The most significant
	 *                                bit of number is the sign bit. The remaining 9 bits are magnitude bits.
	 *                                Negative numbers are represented using two's-complement notation.
	 *                                If number is not a valid binary number, or if number contains more than
	 *                                10 characters (10 bits), BIN2HEX returns the #NUM! error value.
	 * @param    integer $places      The number of characters to use. If places is omitted, BIN2HEX uses the
	 *                                minimum number of characters necessary. Places is useful for padding the
	 *                                return value with leading 0s (zeros).
	 *                                If places is not an integer, it is truncated.
	 *                                If places is nonnumeric, BIN2HEX returns the #VALUE! error value.
	 *                                If places is negative, BIN2HEX returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function BINTOHEX($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)
			{
				$x = (int)$x;
			}
			else
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}
		}
		if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_GNUMERIC)
		{
			$x = floor($x);
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[01]/', $x, $out))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		if (strlen($x) > 10)
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		elseif (strlen($x) == 10)
		{
			//	Two's Complement
			return str_repeat('F', 8) . substr(strtoupper(dechex(bindec(substr($x, -9)))), -2);
		}
		$hexVal = (string)strtoupper(dechex(bindec($x)));

		return self::_nbrConversionFormat($hexVal, $places);
	} //	function BINTOHEX()


	/**
	 * BINTOOCT
	 *
	 * Return a binary value as octal.
	 *
	 * Excel Function:
	 *        BIN2OCT(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x           The binary number (as a string) that you want to convert. The number
	 *                                cannot contain more than 10 characters (10 bits). The most significant
	 *                                bit of number is the sign bit. The remaining 9 bits are magnitude bits.
	 *                                Negative numbers are represented using two's-complement notation.
	 *                                If number is not a valid binary number, or if number contains more than
	 *                                10 characters (10 bits), BIN2OCT returns the #NUM! error value.
	 * @param    integer $places      The number of characters to use. If places is omitted, BIN2OCT uses the
	 *                                minimum number of characters necessary. Places is useful for padding the
	 *                                return value with leading 0s (zeros).
	 *                                If places is not an integer, it is truncated.
	 *                                If places is nonnumeric, BIN2OCT returns the #VALUE! error value.
	 *                                If places is negative, BIN2OCT returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function BINTOOCT($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)
			{
				$x = (int)$x;
			}
			else
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}
		}
		if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_GNUMERIC)
		{
			$x = floor($x);
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[01]/', $x, $out))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		if (strlen($x) > 10)
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		elseif (strlen($x) == 10)
		{
			//	Two's Complement
			return str_repeat('7', 7) . substr(strtoupper(decoct(bindec(substr($x, -9)))), -3);
		}
		$octVal = (string)decoct(bindec($x));

		return self::_nbrConversionFormat($octVal, $places);
	} //	function BINTOOCT()


	/**
	 * DECTOBIN
	 *
	 * Return a decimal value as binary.
	 *
	 * Excel Function:
	 *        DEC2BIN(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x           The decimal integer you want to convert. If number is negative,
	 *                                valid place values are ignored and DEC2BIN returns a 10-character
	 *                                (10-bit) binary number in which the most significant bit is the sign
	 *                                bit. The remaining 9 bits are magnitude bits. Negative numbers are
	 *                                represented using two's-complement notation.
	 *                                If number < -512 or if number > 511, DEC2BIN returns the #NUM! error
	 *                                value.
	 *                                If number is nonnumeric, DEC2BIN returns the #VALUE! error value.
	 *                                If DEC2BIN requires more than places characters, it returns the #NUM!
	 *                                error value.
	 * @param    integer $places      The number of characters to use. If places is omitted, DEC2BIN uses
	 *                                the minimum number of characters necessary. Places is useful for
	 *                                padding the return value with leading 0s (zeros).
	 *                                If places is not an integer, it is truncated.
	 *                                If places is nonnumeric, DEC2BIN returns the #VALUE! error value.
	 *                                If places is zero or negative, DEC2BIN returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function DECTOBIN($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)
			{
				$x = (int)$x;
			}
			else
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[-0123456789.]/', $x, $out))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)floor($x);
		$r = decbin($x);
		if (strlen($r) == 32)
		{
			//	Two's Complement
			$r = substr($r, -10);
		}
		elseif (strlen($r) > 11)
		{
			return PHPExcel_Calculation_Functions::NaN();
		}

		return self::_nbrConversionFormat($r, $places);
	} //	function DECTOBIN()


	/**
	 * DECTOHEX
	 *
	 * Return a decimal value as hex.
	 *
	 * Excel Function:
	 *        DEC2HEX(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x           The decimal integer you want to convert. If number is negative,
	 *                                places is ignored and DEC2HEX returns a 10-character (40-bit)
	 *                                hexadecimal number in which the most significant bit is the sign
	 *                                bit. The remaining 39 bits are magnitude bits. Negative numbers
	 *                                are represented using two's-complement notation.
	 *                                If number < -549,755,813,888 or if number > 549,755,813,887,
	 *                                DEC2HEX returns the #NUM! error value.
	 *                                If number is nonnumeric, DEC2HEX returns the #VALUE! error value.
	 *                                If DEC2HEX requires more than places characters, it returns the
	 *                                #NUM! error value.
	 * @param    integer $places      The number of characters to use. If places is omitted, DEC2HEX uses
	 *                                the minimum number of characters necessary. Places is useful for
	 *                                padding the return value with leading 0s (zeros).
	 *                                If places is not an integer, it is truncated.
	 *                                If places is nonnumeric, DEC2HEX returns the #VALUE! error value.
	 *                                If places is zero or negative, DEC2HEX returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function DECTOHEX($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)
			{
				$x = (int)$x;
			}
			else
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[-0123456789.]/', $x, $out))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)floor($x);
		$r = strtoupper(dechex($x));
		if (strlen($r) == 8)
		{
			//	Two's Complement
			$r = 'FF' . $r;
		}

		return self::_nbrConversionFormat($r, $places);
	} //	function DECTOHEX()


	/**
	 * DECTOOCT
	 *
	 * Return an decimal value as octal.
	 *
	 * Excel Function:
	 *        DEC2OCT(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x           The decimal integer you want to convert. If number is negative,
	 *                                places is ignored and DEC2OCT returns a 10-character (30-bit)
	 *                                octal number in which the most significant bit is the sign bit.
	 *                                The remaining 29 bits are magnitude bits. Negative numbers are
	 *                                represented using two's-complement notation.
	 *                                If number < -536,870,912 or if number > 536,870,911, DEC2OCT
	 *                                returns the #NUM! error value.
	 *                                If number is nonnumeric, DEC2OCT returns the #VALUE! error value.
	 *                                If DEC2OCT requires more than places characters, it returns the
	 *                                #NUM! error value.
	 * @param    integer $places      The number of characters to use. If places is omitted, DEC2OCT uses
	 *                                the minimum number of characters necessary. Places is useful for
	 *                                padding the return value with leading 0s (zeros).
	 *                                If places is not an integer, it is truncated.
	 *                                If places is nonnumeric, DEC2OCT returns the #VALUE! error value.
	 *                                If places is zero or negative, DEC2OCT returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function DECTOOCT($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			if (PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)
			{
				$x = (int)$x;
			}
			else
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[-0123456789.]/', $x, $out))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)floor($x);
		$r = decoct($x);
		if (strlen($r) == 11)
		{
			//	Two's Complement
			$r = substr($r, -10);
		}

		return self::_nbrConversionFormat($r, $places);
	} //	function DECTOOCT()


	/**
	 * HEXTOBIN
	 *
	 * Return a hex value as binary.
	 *
	 * Excel Function:
	 *        HEX2BIN(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x               the hexadecimal number you want to convert. Number cannot
	 *                                    contain more than 10 characters. The most significant bit of
	 *                                    number is the sign bit (40th bit from the right). The remaining
	 *                                    9 bits are magnitude bits. Negative numbers are represented
	 *                                    using two's-complement notation.
	 *                                    If number is negative, HEX2BIN ignores places and returns a
	 *                                    10-character binary number.
	 *                                    If number is negative, it cannot be less than FFFFFFFE00, and
	 *                                    if number is positive, it cannot be greater than 1FF.
	 *                                    If number is not a valid hexadecimal number, HEX2BIN returns
	 *                                    the #NUM! error value.
	 *                                    If HEX2BIN requires more than places characters, it returns
	 *                                    the #NUM! error value.
	 * @param    integer $places          The number of characters to use. If places is omitted,
	 *                                    HEX2BIN uses the minimum number of characters necessary. Places
	 *                                    is useful for padding the return value with leading 0s (zeros).
	 *                                    If places is not an integer, it is truncated.
	 *                                    If places is nonnumeric, HEX2BIN returns the #VALUE! error value.
	 *                                    If places is negative, HEX2BIN returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function HEXTOBIN($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[0123456789ABCDEF]/', strtoupper($x), $out))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		$binVal = decbin(hexdec($x));

		return substr(self::_nbrConversionFormat($binVal, $places), -10);
	} //	function HEXTOBIN()


	/**
	 * HEXTODEC
	 *
	 * Return a hex value as decimal.
	 *
	 * Excel Function:
	 *        HEX2DEC(x)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string $x            The hexadecimal number you want to convert. This number cannot
	 *                                contain more than 10 characters (40 bits). The most significant
	 *                                bit of number is the sign bit. The remaining 39 bits are magnitude
	 *                                bits. Negative numbers are represented using two's-complement
	 *                                notation.
	 *                                If number is not a valid hexadecimal number, HEX2DEC returns the
	 *                                #NUM! error value.
	 *
	 * @return    string
	 */
	public static function HEXTODEC($x) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);

		if (is_bool($x))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[0123456789ABCDEF]/', strtoupper($x), $out))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}

		return hexdec($x);
	} //	function HEXTODEC()


	/**
	 * HEXTOOCT
	 *
	 * Return a hex value as octal.
	 *
	 * Excel Function:
	 *        HEX2OCT(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x               The hexadecimal number you want to convert. Number cannot
	 *                                    contain more than 10 characters. The most significant bit of
	 *                                    number is the sign bit. The remaining 39 bits are magnitude
	 *                                    bits. Negative numbers are represented using two's-complement
	 *                                    notation.
	 *                                    If number is negative, HEX2OCT ignores places and returns a
	 *                                    10-character octal number.
	 *                                    If number is negative, it cannot be less than FFE0000000, and
	 *                                    if number is positive, it cannot be greater than 1FFFFFFF.
	 *                                    If number is not a valid hexadecimal number, HEX2OCT returns
	 *                                    the #NUM! error value.
	 *                                    If HEX2OCT requires more than places characters, it returns
	 *                                    the #NUM! error value.
	 * @param    integer $places          The number of characters to use. If places is omitted, HEX2OCT
	 *                                    uses the minimum number of characters necessary. Places is
	 *                                    useful for padding the return value with leading 0s (zeros).
	 *                                    If places is not an integer, it is truncated.
	 *                                    If places is nonnumeric, HEX2OCT returns the #VALUE! error
	 *                                    value.
	 *                                    If places is negative, HEX2OCT returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function HEXTOOCT($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)$x;
		if (strlen($x) > preg_match_all('/[0123456789ABCDEF]/', strtoupper($x), $out))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		$octVal = decoct(hexdec($x));

		return self::_nbrConversionFormat($octVal, $places);
	} //	function HEXTOOCT()


	/**
	 * OCTTOBIN
	 *
	 * Return an octal value as binary.
	 *
	 * Excel Function:
	 *        OCT2BIN(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x               The octal number you want to convert. Number may not
	 *                                    contain more than 10 characters. The most significant
	 *                                    bit of number is the sign bit. The remaining 29 bits
	 *                                    are magnitude bits. Negative numbers are represented
	 *                                    using two's-complement notation.
	 *                                    If number is negative, OCT2BIN ignores places and returns
	 *                                    a 10-character binary number.
	 *                                    If number is negative, it cannot be less than 7777777000,
	 *                                    and if number is positive, it cannot be greater than 777.
	 *                                    If number is not a valid octal number, OCT2BIN returns
	 *                                    the #NUM! error value.
	 *                                    If OCT2BIN requires more than places characters, it
	 *                                    returns the #NUM! error value.
	 * @param    integer $places          The number of characters to use. If places is omitted,
	 *                                    OCT2BIN uses the minimum number of characters necessary.
	 *                                    Places is useful for padding the return value with
	 *                                    leading 0s (zeros).
	 *                                    If places is not an integer, it is truncated.
	 *                                    If places is nonnumeric, OCT2BIN returns the #VALUE!
	 *                                    error value.
	 *                                    If places is negative, OCT2BIN returns the #NUM! error
	 *                                    value.
	 *
	 * @return    string
	 */
	public static function OCTTOBIN($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)$x;
		if (preg_match_all('/[01234567]/', $x, $out) != strlen($x))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		$r = decbin(octdec($x));

		return self::_nbrConversionFormat($r, $places);
	} //	function OCTTOBIN()


	/**
	 * OCTTODEC
	 *
	 * Return an octal value as decimal.
	 *
	 * Excel Function:
	 *        OCT2DEC(x)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string $x            The octal number you want to convert. Number may not contain
	 *                                more than 10 octal characters (30 bits). The most significant
	 *                                bit of number is the sign bit. The remaining 29 bits are
	 *                                magnitude bits. Negative numbers are represented using
	 *                                two's-complement notation.
	 *                                If number is not a valid octal number, OCT2DEC returns the
	 *                                #NUM! error value.
	 *
	 * @return    string
	 */
	public static function OCTTODEC($x) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);

		if (is_bool($x))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)$x;
		if (preg_match_all('/[01234567]/', $x, $out) != strlen($x))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}

		return octdec($x);
	} //	function OCTTODEC()


	/**
	 * OCTTOHEX
	 *
	 * Return an octal value as hex.
	 *
	 * Excel Function:
	 *        OCT2HEX(x[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string  $x               The octal number you want to convert. Number may not contain
	 *                                    more than 10 octal characters (30 bits). The most significant
	 *                                    bit of number is the sign bit. The remaining 29 bits are
	 *                                    magnitude bits. Negative numbers are represented using
	 *                                    two's-complement notation.
	 *                                    If number is negative, OCT2HEX ignores places and returns a
	 *                                    10-character hexadecimal number.
	 *                                    If number is not a valid octal number, OCT2HEX returns the
	 *                                    #NUM! error value.
	 *                                    If OCT2HEX requires more than places characters, it returns
	 *                                    the #NUM! error value.
	 * @param    integer $places          The number of characters to use. If places is omitted, OCT2HEX
	 *                                    uses the minimum number of characters necessary. Places is useful
	 *                                    for padding the return value with leading 0s (zeros).
	 *                                    If places is not an integer, it is truncated.
	 *                                    If places is nonnumeric, OCT2HEX returns the #VALUE! error value.
	 *                                    If places is negative, OCT2HEX returns the #NUM! error value.
	 *
	 * @return    string
	 */
	public static function OCTTOHEX($x, $places = null) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);
		$places = PHPExcel_Calculation_Functions::flattenSingleValue($places);

		if (is_bool($x))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$x = (string)$x;
		if (preg_match_all('/[01234567]/', $x, $out) != strlen($x))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		$hexVal = strtoupper(dechex(octdec($x)));

		return self::_nbrConversionFormat($hexVal, $places);
	} //	function OCTTOHEX()


	/**
	 * COMPLEX
	 *
	 * Converts real and imaginary coefficients into a complex number of the form x + yi or x + yj.
	 *
	 * Excel Function:
	 *        COMPLEX(realNumber,imaginary[,places])
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    float  $realNumber           The real coefficient of the complex number.
	 * @param    float  $imaginary            The imaginary coefficient of the complex number.
	 * @param    string $suffix               The suffix for the imaginary component of the complex number.
	 *                                        If omitted, the suffix is assumed to be "i".
	 *
	 * @return    string
	 */
	public static function COMPLEX($realNumber = 0.0, $imaginary = 0.0, $suffix = 'i') {
		$realNumber = (is_null($realNumber)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($realNumber);
		$imaginary = (is_null($imaginary)) ? 0.0 : PHPExcel_Calculation_Functions::flattenSingleValue($imaginary);
		$suffix = (is_null($suffix)) ? 'i' : PHPExcel_Calculation_Functions::flattenSingleValue($suffix);

		if (((is_numeric($realNumber)) && (is_numeric($imaginary))) && (($suffix == 'i') || ($suffix == 'j') || ($suffix == '')))
		{
			$realNumber = (float)$realNumber;
			$imaginary = (float)$imaginary;

			if ($suffix == '')
				$suffix = 'i';
			if ($realNumber == 0.0)
			{
				if ($imaginary == 0.0)
				{
					return (string)'0';
				}
				elseif ($imaginary == 1.0)
				{
					return (string)$suffix;
				}
				elseif ($imaginary == -1.0)
				{
					return (string)'-' . $suffix;
				}

				return (string)$imaginary . $suffix;
			}
			elseif ($imaginary == 0.0)
			{
				return (string)$realNumber;
			}
			elseif ($imaginary == 1.0)
			{
				return (string)$realNumber . '+' . $suffix;
			}
			elseif ($imaginary == -1.0)
			{
				return (string)$realNumber . '-' . $suffix;
			}
			if ($imaginary > 0)
			{
				$imaginary = (string)'+' . $imaginary;
			}

			return (string)$realNumber . $imaginary . $suffix;
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function COMPLEX()


	/**
	 * IMAGINARY
	 *
	 * Returns the imaginary coefficient of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMAGINARY(complexNumber)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string $complexNumber        The complex number for which you want the imaginary
	 *                                        coefficient.
	 *
	 * @return    float
	 */
	public static function IMAGINARY($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		return $parsedComplex['imaginary'];
	} //	function IMAGINARY()


	/**
	 * IMREAL
	 *
	 * Returns the real coefficient of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMREAL(complexNumber)
	 *
	 * @access    public
	 * @category  Engineering Functions
	 *
	 * @param    string $complexNumber The complex number for which you want the real coefficient.
	 *
	 * @return    float
	 */
	public static function IMREAL($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		return $parsedComplex['real'];
	} //	function IMREAL()


	/**
	 * IMABS
	 *
	 * Returns the absolute value (modulus) of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMABS(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the absolute value.
	 *
	 * @return    float
	 */
	public static function IMABS($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		return sqrt(($parsedComplex['real'] * $parsedComplex['real']) + ($parsedComplex['imaginary'] * $parsedComplex['imaginary']));
	} //	function IMABS()


	/**
	 * IMARGUMENT
	 *
	 * Returns the argument theta of a complex number, i.e. the angle in radians from the real
	 * axis to the representation of the number in polar coordinates.
	 *
	 * Excel Function:
	 *        IMARGUMENT(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the argument theta.
	 *
	 * @return    float
	 */
	public static function IMARGUMENT($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if ($parsedComplex['real'] == 0.0)
		{
			if ($parsedComplex['imaginary'] == 0.0)
			{
				return 0.0;
			}
			elseif ($parsedComplex['imaginary'] < 0.0)
			{
				return M_PI / -2;
			}
			else
			{
				return M_PI / 2;
			}
		}
		elseif ($parsedComplex['real'] > 0.0)
		{
			return atan($parsedComplex['imaginary'] / $parsedComplex['real']);
		}
		elseif ($parsedComplex['imaginary'] < 0.0)
		{
			return 0 - (M_PI - atan(abs($parsedComplex['imaginary']) / abs($parsedComplex['real'])));
		}
		else
		{
			return M_PI - atan($parsedComplex['imaginary'] / abs($parsedComplex['real']));
		}
	} //	function IMARGUMENT()


	/**
	 * IMCONJUGATE
	 *
	 * Returns the complex conjugate of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMCONJUGATE(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the conjugate.
	 *
	 * @return    string
	 */
	public static function IMCONJUGATE($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if ($parsedComplex['imaginary'] == 0.0)
		{
			return $parsedComplex['real'];
		}
		else
		{
			return self::_cleanComplex(self::COMPLEX($parsedComplex['real'], 0 - $parsedComplex['imaginary'], $parsedComplex['suffix']));
		}
	} //	function IMCONJUGATE()


	/**
	 * IMCOS
	 *
	 * Returns the cosine of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMCOS(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the cosine.
	 *
	 * @return    string|float
	 */
	public static function IMCOS($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if ($parsedComplex['imaginary'] == 0.0)
		{
			return cos($parsedComplex['real']);
		}
		else
		{
			return self::IMCONJUGATE(self::COMPLEX(cos($parsedComplex['real']) * cosh($parsedComplex['imaginary']), sin($parsedComplex['real']) * sinh($parsedComplex['imaginary']), $parsedComplex['suffix']));
		}
	} //	function IMCOS()


	/**
	 * IMSIN
	 *
	 * Returns the sine of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMSIN(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the sine.
	 *
	 * @return    string|float
	 */
	public static function IMSIN($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if ($parsedComplex['imaginary'] == 0.0)
		{
			return sin($parsedComplex['real']);
		}
		else
		{
			return self::COMPLEX(sin($parsedComplex['real']) * cosh($parsedComplex['imaginary']), cos($parsedComplex['real']) * sinh($parsedComplex['imaginary']), $parsedComplex['suffix']);
		}
	} //	function IMSIN()


	/**
	 * IMSQRT
	 *
	 * Returns the square root of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMSQRT(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the square root.
	 *
	 * @return    string
	 */
	public static function IMSQRT($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		$theta = self::IMARGUMENT($complexNumber);
		$d1 = cos($theta / 2);
		$d2 = sin($theta / 2);
		$r = sqrt(sqrt(($parsedComplex['real'] * $parsedComplex['real']) + ($parsedComplex['imaginary'] * $parsedComplex['imaginary'])));

		if ($parsedComplex['suffix'] == '')
		{
			return self::COMPLEX($d1 * $r, $d2 * $r);
		}
		else
		{
			return self::COMPLEX($d1 * $r, $d2 * $r, $parsedComplex['suffix']);
		}
	} //	function IMSQRT()


	/**
	 * IMLN
	 *
	 * Returns the natural logarithm of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMLN(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the natural logarithm.
	 *
	 * @return    string
	 */
	public static function IMLN($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if (($parsedComplex['real'] == 0.0) && ($parsedComplex['imaginary'] == 0.0))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}

		$logR = log(sqrt(($parsedComplex['real'] * $parsedComplex['real']) + ($parsedComplex['imaginary'] * $parsedComplex['imaginary'])));
		$t = self::IMARGUMENT($complexNumber);

		if ($parsedComplex['suffix'] == '')
		{
			return self::COMPLEX($logR, $t);
		}
		else
		{
			return self::COMPLEX($logR, $t, $parsedComplex['suffix']);
		}
	} //	function IMLN()


	/**
	 * IMLOG10
	 *
	 * Returns the common logarithm (base 10) of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMLOG10(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the common logarithm.
	 *
	 * @return    string
	 */
	public static function IMLOG10($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if (($parsedComplex['real'] == 0.0) && ($parsedComplex['imaginary'] == 0.0))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		elseif (($parsedComplex['real'] > 0.0) && ($parsedComplex['imaginary'] == 0.0))
		{
			return log10($parsedComplex['real']);
		}

		return self::IMPRODUCT(log10(EULER), self::IMLN($complexNumber));
	} //	function IMLOG10()


	/**
	 * IMLOG2
	 *
	 * Returns the base-2 logarithm of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMLOG2(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the base-2 logarithm.
	 *
	 * @return    string
	 */
	public static function IMLOG2($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if (($parsedComplex['real'] == 0.0) && ($parsedComplex['imaginary'] == 0.0))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		elseif (($parsedComplex['real'] > 0.0) && ($parsedComplex['imaginary'] == 0.0))
		{
			return log($parsedComplex['real'], 2);
		}

		return self::IMPRODUCT(log(EULER, 2), self::IMLN($complexNumber));
	} //	function IMLOG2()


	/**
	 * IMEXP
	 *
	 * Returns the exponential of a complex number in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMEXP(complexNumber)
	 *
	 * @param    string $complexNumber The complex number for which you want the exponential.
	 *
	 * @return    string
	 */
	public static function IMEXP($complexNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);

		$parsedComplex = self::_parseComplex($complexNumber);

		if (($parsedComplex['real'] == 0.0) && ($parsedComplex['imaginary'] == 0.0))
		{
			return '1';
		}

		$e = exp($parsedComplex['real']);
		$eX = $e * cos($parsedComplex['imaginary']);
		$eY = $e * sin($parsedComplex['imaginary']);

		if ($parsedComplex['suffix'] == '')
		{
			return self::COMPLEX($eX, $eY);
		}
		else
		{
			return self::COMPLEX($eX, $eY, $parsedComplex['suffix']);
		}
	} //	function IMEXP()


	/**
	 * IMPOWER
	 *
	 * Returns a complex number in x + yi or x + yj text format raised to a power.
	 *
	 * Excel Function:
	 *        IMPOWER(complexNumber,realNumber)
	 *
	 * @param    string $complexNumber The complex number you want to raise to a power.
	 * @param    float  $realNumber    The power to which you want to raise the complex number.
	 *
	 * @return    string
	 */
	public static function IMPOWER($complexNumber, $realNumber) {
		$complexNumber = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
		$realNumber = PHPExcel_Calculation_Functions::flattenSingleValue($realNumber);

		if (!is_numeric($realNumber))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}

		$parsedComplex = self::_parseComplex($complexNumber);

		$r = sqrt(($parsedComplex['real'] * $parsedComplex['real']) + ($parsedComplex['imaginary'] * $parsedComplex['imaginary']));
		$rPower = pow($r, $realNumber);
		$theta = self::IMARGUMENT($complexNumber) * $realNumber;
		if ($theta == 0)
		{
			return 1;
		}
		elseif ($parsedComplex['imaginary'] == 0.0)
		{
			return self::COMPLEX($rPower * cos($theta), $rPower * sin($theta), $parsedComplex['suffix']);
		}
		else
		{
			return self::COMPLEX($rPower * cos($theta), $rPower * sin($theta), $parsedComplex['suffix']);
		}
	} //	function IMPOWER()


	/**
	 * IMDIV
	 *
	 * Returns the quotient of two complex numbers in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMDIV(complexDividend,complexDivisor)
	 *
	 * @param    string $complexDividend The complex numerator or dividend.
	 * @param    string $complexDivisor  The complex denominator or divisor.
	 *
	 * @return    string
	 */
	public static function IMDIV($complexDividend, $complexDivisor) {
		$complexDividend = PHPExcel_Calculation_Functions::flattenSingleValue($complexDividend);
		$complexDivisor = PHPExcel_Calculation_Functions::flattenSingleValue($complexDivisor);

		$parsedComplexDividend = self::_parseComplex($complexDividend);
		$parsedComplexDivisor = self::_parseComplex($complexDivisor);

		if (($parsedComplexDividend['suffix'] != '') && ($parsedComplexDivisor['suffix'] != '') && ($parsedComplexDividend['suffix'] != $parsedComplexDivisor['suffix']))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		if (($parsedComplexDividend['suffix'] != '') && ($parsedComplexDivisor['suffix'] == ''))
		{
			$parsedComplexDivisor['suffix'] = $parsedComplexDividend['suffix'];
		}

		$d1 = ($parsedComplexDividend['real'] * $parsedComplexDivisor['real']) + ($parsedComplexDividend['imaginary'] * $parsedComplexDivisor['imaginary']);
		$d2 = ($parsedComplexDividend['imaginary'] * $parsedComplexDivisor['real']) - ($parsedComplexDividend['real'] * $parsedComplexDivisor['imaginary']);
		$d3 = ($parsedComplexDivisor['real'] * $parsedComplexDivisor['real']) + ($parsedComplexDivisor['imaginary'] * $parsedComplexDivisor['imaginary']);

		$r = $d1 / $d3;
		$i = $d2 / $d3;

		if ($i > 0.0)
		{
			return self::_cleanComplex($r . '+' . $i . $parsedComplexDivisor['suffix']);
		}
		elseif ($i < 0.0)
		{
			return self::_cleanComplex($r . $i . $parsedComplexDivisor['suffix']);
		}
		else
		{
			return $r;
		}
	} //	function IMDIV()


	/**
	 * IMSUB
	 *
	 * Returns the difference of two complex numbers in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMSUB(complexNumber1,complexNumber2)
	 *
	 * @param    string $complexNumber1 The complex number from which to subtract complexNumber2.
	 * @param    string $complexNumber2 The complex number to subtract from complexNumber1.
	 *
	 * @return    string
	 */
	public static function IMSUB($complexNumber1, $complexNumber2) {
		$complexNumber1 = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber1);
		$complexNumber2 = PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber2);

		$parsedComplex1 = self::_parseComplex($complexNumber1);
		$parsedComplex2 = self::_parseComplex($complexNumber2);

		if ((($parsedComplex1['suffix'] != '') && ($parsedComplex2['suffix'] != '')) && ($parsedComplex1['suffix'] != $parsedComplex2['suffix']))
		{
			return PHPExcel_Calculation_Functions::NaN();
		}
		elseif (($parsedComplex1['suffix'] == '') && ($parsedComplex2['suffix'] != ''))
		{
			$parsedComplex1['suffix'] = $parsedComplex2['suffix'];
		}

		$d1 = $parsedComplex1['real'] - $parsedComplex2['real'];
		$d2 = $parsedComplex1['imaginary'] - $parsedComplex2['imaginary'];

		return self::COMPLEX($d1, $d2, $parsedComplex1['suffix']);
	} //	function IMSUB()


	/**
	 * IMSUM
	 *
	 * Returns the sum of two or more complex numbers in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMSUM(complexNumber[,complexNumber[,...]])
	 *
	 * @param    string $complexNumber,... Series of complex numbers to add
	 *
	 * @return    string
	 */
	public static function IMSUM() {
		// Return value
		$returnValue = self::_parseComplex('0');
		$activeSuffix = '';

		// Loop through the arguments
		$aArgs = PHPExcel_Calculation_Functions::flattenArray(func_get_args());
		foreach ($aArgs as $arg)
		{
			$parsedComplex = self::_parseComplex($arg);

			if ($activeSuffix == '')
			{
				$activeSuffix = $parsedComplex['suffix'];
			}
			elseif (($parsedComplex['suffix'] != '') && ($activeSuffix != $parsedComplex['suffix']))
			{
				return PHPExcel_Calculation_Functions::VALUE();
			}

			$returnValue['real'] += $parsedComplex['real'];
			$returnValue['imaginary'] += $parsedComplex['imaginary'];
		}

		if ($returnValue['imaginary'] == 0.0)
		{
			$activeSuffix = '';
		}

		return self::COMPLEX($returnValue['real'], $returnValue['imaginary'], $activeSuffix);
	} //	function IMSUM()


	/**
	 * IMPRODUCT
	 *
	 * Returns the product of two or more complex numbers in x + yi or x + yj text format.
	 *
	 * Excel Function:
	 *        IMPRODUCT(complexNumber[,complexNumber[,...]])
	 *
	 * @param    string $complexNumber,... Series of complex numbers to multiply
	 *
	 * @return    string
	 */
	public static function IMPRODUCT() {
		// Return value
		$returnValue = self::_parseComplex('1');
		$activeSuffix = '';

		// Loop through the arguments
		$aArgs = PHPExcel_Calculation_Functions::flattenArray(func_get_args());
		foreach ($aArgs as $arg)
		{
			$parsedComplex = self::_parseComplex($arg);

			$workValue = $returnValue;
			if (($parsedComplex['suffix'] != '') && ($activeSuffix == ''))
			{
				$activeSuffix = $parsedComplex['suffix'];
			}
			elseif (($parsedComplex['suffix'] != '') && ($activeSuffix != $parsedComplex['suffix']))
			{
				return PHPExcel_Calculation_Functions::NaN();
			}
			$returnValue['real'] = ($workValue['real'] * $parsedComplex['real']) - ($workValue['imaginary'] * $parsedComplex['imaginary']);
			$returnValue['imaginary'] = ($workValue['real'] * $parsedComplex['imaginary']) + ($workValue['imaginary'] * $parsedComplex['real']);
		}

		if ($returnValue['imaginary'] == 0.0)
		{
			$activeSuffix = '';
		}

		return self::COMPLEX($returnValue['real'], $returnValue['imaginary'], $activeSuffix);
	} //	function IMPRODUCT()


	/**
	 *    DELTA
	 *
	 *    Tests whether two values are equal. Returns 1 if number1 = number2; returns 0 otherwise.
	 *    Use this function to filter a set of values. For example, by summing several DELTA
	 *    functions you calculate the count of equal pairs. This function is also known as the
	 *    Kronecker Delta function.
	 *
	 *    Excel Function:
	 *        DELTA(a[,b])
	 *
	 * @param    float $a The first number.
	 * @param    float $b The second number. If omitted, b is assumed to be zero.
	 *
	 * @return    int
	 */
	public static function DELTA($a, $b = 0) {
		$a = PHPExcel_Calculation_Functions::flattenSingleValue($a);
		$b = PHPExcel_Calculation_Functions::flattenSingleValue($b);

		return (int)($a == $b);
	} //	function DELTA()


	/**
	 *    GESTEP
	 *
	 *    Excel Function:
	 *        GESTEP(number[,step])
	 *
	 *    Returns 1 if number >= step; returns 0 (zero) otherwise
	 *    Use this function to filter a set of values. For example, by summing several GESTEP
	 *    functions you calculate the count of values that exceed a threshold.
	 *
	 * @param    float $number            The value to test against step.
	 * @param    float $step              The threshold value.
	 *                                    If you omit a value for step, GESTEP uses zero.
	 *
	 * @return    int
	 */
	public static function GESTEP($number, $step = 0) {
		$number = PHPExcel_Calculation_Functions::flattenSingleValue($number);
		$step = PHPExcel_Calculation_Functions::flattenSingleValue($step);

		return (int)($number >= $step);
	} //	function GESTEP()


	//
	//	Private method to calculate the erf value
	//
	private static $_two_sqrtpi = 1.128379167095512574;

	public static function _erfVal($x) {
		if (abs($x) > 2.2)
		{
			return 1 - self::_erfcVal($x);
		}
		$sum = $term = $x;
		$xsqr = ($x * $x);
		$j = 1;
		do
		{
			$term *= $xsqr / $j;
			$sum -= $term / (2 * $j + 1);
			++$j;
			$term *= $xsqr / $j;
			$sum += $term / (2 * $j + 1);
			++$j;
			if ($sum == 0.0)
			{
				break;
			}
		} while (abs($term / $sum) > PRECISION);

		return self::$_two_sqrtpi * $sum;
	} //	function _erfVal()


	/**
	 *    ERF
	 *
	 *    Returns the error function integrated between the lower and upper bound arguments.
	 *
	 *    Note: In Excel 2007 or earlier, if you input a negative value for the upper or lower bound arguments,
	 *            the function would return a #NUM! error. However, in Excel 2010, the function algorithm was
	 *            improved, so that it can now calculate the function for both positive and negative ranges.
	 *            PHPExcel follows Excel 2010 behaviour, and accepts nagative arguments.
	 *
	 *    Excel Function:
	 *        ERF(lower[,upper])
	 *
	 * @param    float $lower         lower bound for integrating ERF
	 * @param    float $upper         upper bound for integrating ERF.
	 *                                If omitted, ERF integrates between zero and lower_limit
	 *
	 * @return    float
	 */
	public static function ERF($lower, $upper = null) {
		$lower = PHPExcel_Calculation_Functions::flattenSingleValue($lower);
		$upper = PHPExcel_Calculation_Functions::flattenSingleValue($upper);

		if (is_numeric($lower))
		{
			if (is_null($upper))
			{
				return self::_erfVal($lower);
			}
			if (is_numeric($upper))
			{
				return self::_erfVal($upper) - self::_erfVal($lower);
			}
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function ERF()


	//
	//	Private method to calculate the erfc value
	//
	private static $_one_sqrtpi = 0.564189583547756287;

	private static function _erfcVal($x) {
		if (abs($x) < 2.2)
		{
			return 1 - self::_erfVal($x);
		}
		if ($x < 0)
		{
			return 2 - self::ERFC(-$x);
		}
		$a = $n = 1;
		$b = $c = $x;
		$d = ($x * $x) + 0.5;
		$q1 = $q2 = $b / $d;
		$t = 0;
		do
		{
			$t = $a * $n + $b * $x;
			$a = $b;
			$b = $t;
			$t = $c * $n + $d * $x;
			$c = $d;
			$d = $t;
			$n += 0.5;
			$q1 = $q2;
			$q2 = $b / $d;
		} while ((abs($q1 - $q2) / $q2) > PRECISION);

		return self::$_one_sqrtpi * exp(-$x * $x) * $q2;
	} //	function _erfcVal()


	/**
	 *    ERFC
	 *
	 *    Returns the complementary ERF function integrated between x and infinity
	 *
	 *    Note: In Excel 2007 or earlier, if you input a negative value for the lower bound argument,
	 *        the function would return a #NUM! error. However, in Excel 2010, the function algorithm was
	 *        improved, so that it can now calculate the function for both positive and negative x values.
	 *            PHPExcel follows Excel 2010 behaviour, and accepts nagative arguments.
	 *
	 *    Excel Function:
	 *        ERFC(x)
	 *
	 * @param    float $x The lower bound for integrating ERFC
	 *
	 * @return    float
	 */
	public static function ERFC($x) {
		$x = PHPExcel_Calculation_Functions::flattenSingleValue($x);

		if (is_numeric($x))
		{
			return self::_erfcVal($x);
		}

		return PHPExcel_Calculation_Functions::VALUE();
	} //	function ERFC()


	/**
	 *    getConversionGroups
	 *    Returns a list of the different conversion groups for UOM conversions
	 *
	 * @return    array
	 */
	public static function getConversionGroups() {
		$conversionGroups = array();
		foreach (self::$_conversionUnits as $conversionUnit)
		{
			$conversionGroups[] = $conversionUnit['Group'];
		}

		return array_merge(array_unique($conversionGroups));
	} //	function getConversionGroups()


	/**
	 *    getConversionGroupUnits
	 *    Returns an array of units of measure, for a specified conversion group, or for all groups
	 *
	 * @param    string $group The group whose units of measure you want to retrieve
	 *
	 * @return    array
	 */
	public static function getConversionGroupUnits($group = null) {
		$conversionGroups = array();
		foreach (self::$_conversionUnits as $conversionUnit => $conversionGroup)
		{
			if ((is_null($group)) || ($conversionGroup['Group'] == $group))
			{
				$conversionGroups[$conversionGroup['Group']][] = $conversionUnit;
			}
		}

		return $conversionGroups;
	} //	function getConversionGroupUnits()


	/**
	 *    getConversionGroupUnitDetails
	 *
	 * @param    string $group The group whose units of measure you want to retrieve
	 *
	 * @return    array
	 */
	public static function getConversionGroupUnitDetails($group = null) {
		$conversionGroups = array();
		foreach (self::$_conversionUnits as $conversionUnit => $conversionGroup)
		{
			if ((is_null($group)) || ($conversionGroup['Group'] == $group))
			{
				$conversionGroups[$conversionGroup['Group']][] = array(
						'unit' => $conversionUnit,
						'description' => $conversionGroup['Unit Name']
				);
			}
		}

		return $conversionGroups;
	} //	function getConversionGroupUnitDetails()


	/**
	 *    getConversionMultipliers
	 *    Returns an array of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM()
	 *
	 * @return    array of mixed
	 */
	public static function getConversionMultipliers() {
		return self::$_conversionMultipliers;
	} //	function getConversionGroups()


	/**
	 *    CONVERTUOM
	 *
	 *    Converts a number from one measurement system to another.
	 *    For example, CONVERT can translate a table of distances in miles to a table of distances
	 *    in kilometers.
	 *
	 *    Excel Function:
	 *        CONVERT(value,fromUOM,toUOM)
	 *
	 * @param    float  $value   The value in fromUOM to convert.
	 * @param    string $fromUOM The units for value.
	 * @param    string $toUOM   The units for the result.
	 *
	 * @return    float
	 */
	public static function CONVERTUOM($value, $fromUOM, $toUOM) {
		$value = PHPExcel_Calculation_Functions::flattenSingleValue($value);
		$fromUOM = PHPExcel_Calculation_Functions::flattenSingleValue($fromUOM);
		$toUOM = PHPExcel_Calculation_Functions::flattenSingleValue($toUOM);

		if (!is_numeric($value))
		{
			return PHPExcel_Calculation_Functions::VALUE();
		}
		$fromMultiplier = 1.0;
		if (isset(self::$_conversionUnits[$fromUOM]))
		{
			$unitGroup1 = self::$_conversionUnits[$fromUOM]['Group'];
		}
		else
		{
			$fromMultiplier = substr($fromUOM, 0, 1);
			$fromUOM = substr($fromUOM, 1);
			if (isset(self::$_conversionMultipliers[$fromMultiplier]))
			{
				$fromMultiplier = self::$_conversionMultipliers[$fromMultiplier]['multiplier'];
			}
			else
			{
				return PHPExcel_Calculation_Functions::NA();
			}
			if ((isset(self::$_conversionUnits[$fromUOM])) && (self::$_conversionUnits[$fromUOM]['AllowPrefix']))
			{
				$unitGroup1 = self::$_conversionUnits[$fromUOM]['Group'];
			}
			else
			{
				return PHPExcel_Calculation_Functions::NA();
			}
		}
		$value *= $fromMultiplier;

		$toMultiplier = 1.0;
		if (isset(self::$_conversionUnits[$toUOM]))
		{
			$unitGroup2 = self::$_conversionUnits[$toUOM]['Group'];
		}
		else
		{
			$toMultiplier = substr($toUOM, 0, 1);
			$toUOM = substr($toUOM, 1);
			if (isset(self::$_conversionMultipliers[$toMultiplier]))
			{
				$toMultiplier = self::$_conversionMultipliers[$toMultiplier]['multiplier'];
			}
			else
			{
				return PHPExcel_Calculation_Functions::NA();
			}
			if ((isset(self::$_conversionUnits[$toUOM])) && (self::$_conversionUnits[$toUOM]['AllowPrefix']))
			{
				$unitGroup2 = self::$_conversionUnits[$toUOM]['Group'];
			}
			else
			{
				return PHPExcel_Calculation_Functions::NA();
			}
		}
		if ($unitGroup1 != $unitGroup2)
		{
			return PHPExcel_Calculation_Functions::NA();
		}

		if (($fromUOM == $toUOM) && ($fromMultiplier == $toMultiplier))
		{
			//	We've already factored $fromMultiplier into the value, so we need
			//		to reverse it again
			return $value / $fromMultiplier;
		}
		elseif ($unitGroup1 == 'Temperature')
		{
			if (($fromUOM == 'F') || ($fromUOM == 'fah'))
			{
				if (($toUOM == 'F') || ($toUOM == 'fah'))
				{
					return $value;
				}
				else
				{
					$value = (($value - 32) / 1.8);
					if (($toUOM == 'K') || ($toUOM == 'kel'))
					{
						$value += 273.15;
					}

					return $value;
				}
			}
			elseif ((($fromUOM == 'K') || ($fromUOM == 'kel')) && (($toUOM == 'K') || ($toUOM == 'kel')))
			{
				return $value;
			}
			elseif ((($fromUOM == 'C') || ($fromUOM == 'cel')) && (($toUOM == 'C') || ($toUOM == 'cel')))
			{
				return $value;
			}
			if (($toUOM == 'F') || ($toUOM == 'fah'))
			{
				if (($fromUOM == 'K') || ($fromUOM == 'kel'))
				{
					$value -= 273.15;
				}

				return ($value * 1.8) + 32;
			}
			if (($toUOM == 'C') || ($toUOM == 'cel'))
			{
				return $value - 273.15;
			}

			return $value + 273.15;
		}

		return ($value * self::$_unitConversions[$unitGroup1][$fromUOM][$toUOM]) / $toMultiplier;
	} //	function CONVERTUOM()

} //	class PHPExcel_Calculation_Engineering
